[prsnck]

Hi All Rx folks,

I have a 2003 dec Rx135 4 speed Yamaha run 39k km. From the time I laid the hand on this Yam, I have regularly maintained it well and serviced at Yamaha Auth serv center only.

Its stock with the only change being exhaust chamber is changed to rx 100 one, with pipe added for exhaust beat note. Always topped with Yamalube oil only. Always used to give Yamaha Auth center, panache in old madras road, bangalore.

Quickly will get into query in case you all know about this or would have undergone this scenario.

The bore (top portion) of engine gets heated within 5-6 km of ride. For the first time ever in my life, after getting hold of this machine, I forgot to top up Yamalube and it must have run couple of days with empty engine oil. So while I had a look yesterday, it was dried and I topped up with Yamalube. Still the engine bore gets well heated very soon, while riding for about 4-5 km.

I just took this to my regular mechanic who has serviced this beast from the time I took, he told I was damn lucky so that bore was about to sieze it seems. The guy is pretty well expert in 2 storke specialized on yamaha ones, since he was part of Yamaha Auth service center, at a mechanic and senior level.

He removed the air block, and ensured more engine oil flow is there to engine and told that I have just escaped and all is well. He told that much of heat is common during these days and its ok. Now also I am not fully convinced since its heating the same way I saw yesterday.

Also I am getting a minor bhur bhur sound from engine, not sure is that anything to do with engine tuning or not. Should I wait for some more days and see.


Any advice here.

**mods - Please edit/move/merge in case thread is not appropraite here.

Thanks
prsn

[rocky080]

hey prsnk the bhur bhur sound is from the connecting rod( it called gajan pin bearing i think) or engine bearings which you might have messed up, by driving without oil.If the mechanic says that the connecting rod(crank shaft) wobble is not much you can drive it without any problems but this sound will not go away. Your cylinder would also have suffered a little bit of damage(a couple of scratches) but nothing to worry about.

hope this helps. And please make sure that you have sufficient oil from the next time.If you seize you cylinder you will have to get it rebored which you can do only a limited number of times and a new block is almost impossible to find.

[aargee]

Originally Posted by prsnck

Its stock with the only change being exhaust chamber is changed to rx 100 one, with pipe added for exhaust beat note.

I assume you've changed the exhaust (silencer/muffler) along with the core to RX100/RXG. Correct me, if it is otherwise.

Originally Posted by prsnck

The bore (top portion) of engine gets heated within 5-6 km of ride.

The top portion is head & the bottom portion is the bore or cylinder. So I assume you're talking about cylinder head.

Originally Posted by prsnck

he told I was damn lucky so that bore was about to sieze it seems.

Trust him - he's right. You're lucky.

Originally Posted by prsnck

He removed the air block, and ensured more engine oil flow is there to engine and told that I have just escaped and all is well. He told that much of heat is common during these days and its ok.

Air block from where? Where's it coming from? Are you referring to the fact that he adjusted the carb's air screw more so that there's more air inflow to the cylinder?

IMO, whatever you mech did is right. Basically, he's trying to add more oil so that the wear & tear (proabably with the rings) is compensated by the excess carbon formation.

Did you check the condition of the rings? Were they OK? Do a compression test first with your mech & see the reading. Also change the head gaskets if the cylinder was not opened for long (which I assume). Don't worry on anything else.

EDIT - What size of piston are you running? I hope they're standard size pistons. Pls correct me otherwise.

[vrprabhu]

Originally Posted by rocky080

If the mechanic says that the connecting rod(crank shaft) wobble is not much you can drive it without any problems but this sound will not go away.

Would you permit me to disagree? A slight out of alignment crank is alright, but the situation will get worse over a period of time and will warrant serious repairs later - especially if you are type to crack the throttle every time you see a open stretch!

I would advise you to the check the piston rings first - and how they seat on the piston. The condition of both will indicate the extent of damage due to lack of oil.

If your yamaha technician is an expert, get the timing also checked. The reed valve polishing / setting and crank timing require some involved effort and something wrong here generally gives out an unusual noise / beat to the engine.

[SPIKE ARRESTOR]

Originally Posted by prsnck

He removed the air block, and ensured more engine oil flow is there to engine and told that I have just escaped and all is well.

What do you mean by air block?

Originally Posted by rocky080

hey prsnk the bhur bhur sound is from the connecting rod( it called gajan pin bearing i think) or engine bearings which you might have messed up, by driving without oil.

That is called as a gudgeon pin/piston pin, you will get grinding noises if your bearings are faulty, noises generated from parts having linear and rotatory motion are different.

Originally Posted by aargee

IMO, whatever you mech did is right. Basically, he's trying to add more oil so that the wear & tear (proabably with the rings) is compensated by the excess carbon formation.

He is trying to add more oil as it will act as a layer between the piston and the cylinder, i don't think formation of carbon due to the burnt fuel/oil will prevent any wear and tear of the components.

Spike

[aargee]

Originally Posted by vrprabhu

I would advise you to the check the piston rings first - and how they seat on the piston. The condition of both will indicate the extent of damage due to lack of oil.

+1; lack of oil - first part to get worn out is rings followed by piston.

Originally Posted by SPIKE ARRESTOR

you will get grinding noises if your bearings are faulty, noises generated from parts having linear and rotatory motion are different.

+1

Originally Posted by SPIKE ARRESTOR

He is trying to add more oil as it will act as a layer between the piston and the cylinder, i don't think formation of carbon due to the burnt fuel/oil will prevent any wear and tear of the components.

The addition of extra oil is for, direct answer - extra lubrication & indirect answer - for carbon formation. Allow me to explain; I hope you'll agree that lack of oil leads to more wear & tear & thus there's a possiblity of rings wearing out before the piston could. Now, due to the worn out, understand here that worn out is not even in mm, its less than few mm, causes weird noises, sluggish pulls, increased vibrations & even unsmooth engine. Now to clear up that extra gap, you've 2 options; change the rings which makes you to treat the engine like a running period or use the same rings but allow carbon to settle to close the gap.

Just think about this - why would I want to allow more oil circulation now because I did not lubricate for last several days? Is it to compensate the oil for last several days? I don't think so. If I were adding X amount of oil till last week, shouldn't I be adding the same X amount from today (provided I was running without 2T oil for last 1 week)? What has changed since last week? The cylinder? The head? The carb? The pump? Absolutely nothing right? So why would I add circulate more?

Infact I would recommend adding good 2T oil (premixture) along with petrol for few days.

[rocky080]

Originally Posted by vrprabhu

Would you permit me to disagree? A slight out of alignment crank is alright, but the situation will get worse over a period of time and will warrant serious repairs later - especially if you are type to crack the throttle every time you see a open stretch!
.

I totally agree with you regarding the wobble that's what i meant that its ok for now. but this noise will remain until he gets it fixed later.

[somspaple]

i agree with aargee and SPIKE ARRESTOR

but bore getting heated can be because of excess oil:
more oil in the petrol -> less fuel to burn -> engine runs lean leading to hot cylinders.

check your plugs also : if you have changed to your plugs recently check if it is right ones: the stock recommended NGK BH7PS (hope 'm correct) can run hot (even 'm running it).

[SPIKE ARRESTOR]

Originally Posted by aargee

Just think about this - why would I want to allow more oil circulation now because I did not lubricate for last several days? Is it to compensate the oil for last several days? I don't think so. If I were adding X amount of oil till last week, shouldn't I be adding the same X amount from today (provided I was running without 2T oil for last 1 week)? What has changed since last week? The cylinder? The head? The carb? The pump? Absolutely nothing right? So why would I add circulate more?

Aargee, i agree with your argument. Infact, i never said that addition of more oil was to compensate the lack of oil for the past few days of drive. What i meant was the formation of carbon would not act as a "seal" the way in which the piston rings would.

Spike

[SpinWizard]

My 2 Cents -
Air block is being refered to the inlet of the oil to the Engine/Gear box. I own a 2002 RX and this is a familiar problem. Generally while re-filling the oil, the service guys need to open the inlet completely and forcefully pump some oil, after which refilling can be done. Most of the times(and especially when empty) just refilling wont do. The block has to be removed only then the oil actually reaches the engine.

[vrprabhu]

Originally Posted by SpinWizard

Air block is being refered to the inlet of the oil to the Engine/Gear box.

I though the 2T oil was in a separate tank which was operated by its own pump (operated by the cable included in the accelerator cable which splits into two before it reaches the carb).

And, the engine oil was separate, which is used for the gear / clutch assembly.

If this be case, airlock can happen only in 2T oil pump, which will affect only the engine. Whereas the lower arm (crankshaft) connected to the gears has its own oil, which normally does not dry unless all oil has leaked out.

[prsnck]

Originally Posted by SpinWizard

My 2 Cents -
Air block is being refered to the inlet of the oil to the Engine/Gear box. I own a 2002 RX and this is a familiar problem. Generally while re-filling the oil, the service guys need to open the inlet completely and forcefully pump some oil, after which refilling can be done. Most of the times(and especially when empty) just refilling wont do. The block has to be removed only then the oil actually reaches the engine.

Exactly and well said SpinWizard. This was what has been done in the morning, He did remove the right bottom portion metal block with star screw drivers, where the air was blocked in the pipe.

There was some fuel/oil spillage from that portion as he kept on accelerating and was inlet box restored back. Also he removed the pipe conneting to a small nozzle at top portion just above cylinder head, and did the acceleration again to remove the air block at the starting portion too, I believe.

rgrds
prsn

[SpinWizard]

Yes Vrprabhu, I concur.
prsnck, is referring to the 2T oil pump itself. If this oil runs out, would it not cause heating problems ?

[Sankar]

Originally Posted by prsnck

Hi All Rx folks,

I have a 2003 dec Rx135 4 speed Yamaha run 39k km. From the time I laid the hand on this Yam, I have regularly maintained it well and serviced at Yamaha Auth serv center only.

Its stock with the only change being exhaust chamber is changed to rx 100 one, with pipe added for exhaust beat note. Always topped with Yamalube oil only. Always used to give Yamaha Auth center, panache in old madras road, bangalore.

Quickly will get into query in case you all know about this or would have undergone this scenario.

The bore (top portion) of engine gets heated within 5-6 km of ride. For the first time ever in my life, after getting hold of this machine, I forgot to top up Yamalube and it must have run couple of days with empty engine oil. So while I had a look yesterday, it was dried and I topped up with Yamalube. Still the engine bore gets well heated very soon, while riding for about 4-5 km.

I just took this to my regular mechanic who has serviced this beast from the time I took, he told I was damn lucky so that bore was about to sieze it seems. The guy is pretty well expert in 2 storke specialized on yamaha ones, since he was part of Yamaha Auth service center, at a mechanic and senior level.

He removed the air block, and ensured more engine oil flow is there to engine and told that I have just escaped and all is well. He told that much of heat is common during these days and its ok. Now also I am not fully convinced since its heating the same way I saw yesterday.

Also I am getting a minor bhur bhur sound from engine, not sure is that anything to do with engine tuning or not. Should I wait for some more days and see.


Any advice here.

**mods - Please edit/move/merge in case thread is not appropraite here.

Thanks
prsn

Info you've provided is a bit sketchy, need more info to diagnose.

Ok so oil supply is restored after your mech bleeded the oil line, good. Check if the bike is smoking as usual to make sure oil is indeed burning.

Your issue is that the engine head is getting heated up more than it usually does even during short rides? And it used to heat up even before the oil tank ran dry, is it?

How much does it heat up? Does it heat up bad enough so that you can feel the heat on your legs when you ride or while at a traffic halt?

Is this bhur bhur sound like the sound when you almost run out of petrol?

When you cut the throttle does the RPM drop as quickly or do you get hanging RPM (engine rpm doesn't reduce as quick as you cut the throttle)?

How's the mileage? Very good, normal or bad?

Don't worry about your gudgeon pin & all, if the gudgeon pin is on its way out you'll get tak tak sound from near the head.

Originally Posted by SpinWizard

Yes Vrprabhu, I concur.
prsnck, is referring to the 2T oil pump itself. If this oil runs out, would it not cause heating problems ?

Yes it does, air gets in through there, leaning out the mixture resulting in overheating.

[jayakrishnan_v]

1. Pls do make sure that the oil level in the tank is dropping as you use it along with the usage of bike and also the smoke is coming out from the exhaust.
2. If the oil level thru the pump is increased then see first before you add more oil thru the tank as premix as this could again lean out your air-fuel mixture. If so get your mech to increase the petrol flow as well by adjusting the air screw of your carb.
3. check the piston rings and its ring end gap. If not within the limit change it. But when you take out the head to inspect the piston and rings, make sure the crank rod is not having play more than allowed.
4. change the head gasket and for some initial 1000kms take it easy to get the seating of rings to be brought back to the necessary spec. If the rings are giving their way out then you will see loss of compression and also the slow speed wont last.
5. Also check for any air leaks for eg: in the rubber tube from the airfilter to the carb as well and your fuel filter is clean as well.

Ride safe...